Flame-retardant anti-aging composite material and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, in particular to a flame-retardant anti-aging composite material and a preparation method thereof. Comprising the following components in parts by weight: 60-80 parts of nylon resin, 15-25 parts of filler, 5-18 parts of a halogen-free flame retardant, 3-7 parts of a solubilizer, 2.1-3.5 parts of a lubricant, 0.6-1.2 parts of an antioxidant, 0.5-2.4 parts of a light stabilizer and 1-3 parts of a plasticizer, the halogen-free flame retardant is an alkali lignin-based nitrogen-phosphorus flame retardant, the alkali lignin-based nitrogen-phosphorus flame retardant is prepared by performing carboxymethylation modification on industrial alkali lignin through sodium chloroacetate to prepare water-soluble carboxymethyl alkali lignin, and taking glyoxal, urea and melamine as raw materials to synthesize melamine urea-formaldehyde resin. And then compounding the carboxymethyl alkali lignin, melamine urea-formaldehyde resin and diammonium hydrogen phosphate to prepare the water-retaining agent. The material has the advantages of high mechanical strength, good balance between rigidity and toughness, and excellent high-temperature performance and chemical resistance.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to a flame-retardant and anti-aging composite material and its preparation method. Background Technology

[0002] Nylon materials possess excellent mechanical properties, especially after reinforcement with glass fiber, which significantly improves their tensile strength, rigidity, and impact strength, leading to their widespread use in the automotive, home appliance, and electronics industries. During the injection molding of glass fiber reinforced nylon, factors such as pores, inserts, and multiple gates in the mold can cause multidirectional flow, resulting in weld lines when the molten fluids meet. The mechanical strength at these weld lines is significantly reduced, affecting the overall mechanical properties of the product. For pure nylon, weld line strength is primarily influenced by the entanglement and orientation of molecules at the interface when the melts meet. In glass fiber reinforced nylon, the reduction in weld line strength is more pronounced. This is mainly because the glass fibers are oriented along the weld line direction and cannot penetrate both sides of the weld line, resulting in a larger decrease in weld line strength.

[0003] Currently, the following problems exist: (1) The addition of flame retardants usually leads to a decrease in the physical properties of nylon materials, such as impact strength, flexural strength and tensile strength; (2) Although the filler glass fiber in nylon materials can improve the strength of the material, the poor bonding between glass fiber and nylon resin interface can easily cause the "wick effect", which weakens the flame retardancy and exacerbates the decline in impact performance. Summary of the Invention

[0004] This invention provides a flame-retardant and anti-aging composite material and its preparation method. The resulting flame-retardant and anti-aging composite material exhibits high mechanical strength, a good balance between rigidity and toughness, and excellent high-temperature performance and chemical resistance. By adding fillers, halogen-free flame retardants, solubilizers, lubricants, antioxidants, light stabilizers, and plasticizers, the flame-retardant and anti-aging composite material lowers the material surface temperature, inhibits the generation of combustible gases, and simultaneously possesses high toughness, wear resistance, and self-lubricating properties.

[0005] In a first aspect, the present invention provides a flame-retardant and anti-aging composite material comprising the following components in parts by weight: 60-80 parts nylon resin, 15-25 parts filler, 5-18 parts halogen-free flame retardant, 3-7 parts solubilizer, 2.1-3.5 parts lubricant, 0.6-1.2 parts antioxidant, 0.5-2.4 parts light stabilizer and 1-3 parts plasticizer; The halogen-free flame retardant is an alkali lignin-based nitrogen-phosphorus flame retardant. The alkali lignin-based nitrogen-phosphorus flame retardant is prepared by carboxylation modification of industrial alkali lignin with sodium chloroacetate to obtain water-soluble carboxymethyl alkali lignin. Melamine urea-formaldehyde resin is then synthesized using glyoxal, urea, and melamine as raw materials. Subsequently, carboxymethyl alkali lignin, melamine urea-formaldehyde resin, and diammonium hydrogen phosphate are compounded to obtain the final product.

[0006] Preferably, the mass ratio of carboxymethyl alkali lignin, melamine urea-formaldehyde resin and diammonium hydrogen phosphate is 1-2:2-3:1.

[0007] Preferably, the mass ratio of glyoxal, urea and melamine in the melamine-urea-formaldehyde resin is 1-4:2-3:1-2.

[0008] Preferably, the filler is one or more of nano-titanium dioxide, nano-zinc oxide, nano-montmorillonite, boron nitride, and nano-calcium titanate.

[0009] Preferably, the solubilizer is hexadecyltrimethylammonium bromide or maleic anhydride-grafted polyolefin.

[0010] Preferably, the antioxidant is one or more of bis(2,4-dicumylphenyl)pentaerythritol diphosphite, butylated hydroxytoluene, pentaerythritol tetra(3-lauryl thiopropionate), and sorbitol.

[0011] Preferably, the light stabilizer is one or more of bis-2,2,6,6-tetramethylpiperidine sebacate, polysuccinate, and bis(2,2,6,6-tetramethylpiperidine) sebacate.

[0012] Preferably, the plasticizer is one or more of di(2-ethylhexyl) phthalate, tris(1,3-dichloroisopropyl) phosphate, triisopropylphenyl phosphate, diphenylisodecyl phosphate, and methyl pentachlorostearate.

[0013] Secondly, the present invention provides a method for preparing a flame-retardant and anti-aging composite material, comprising the following steps: (1) Mix nylon resin, filler, halogen-free flame retardant, solubilizer, lubricant, antioxidant, light stabilizer and plasticizer to obtain a preliminary mixture; (2) The initial mixture is melted to obtain a molten mixture; (3) The molten mixture is dried to obtain a flame-retardant and anti-aging composite material.

[0014] Preferably, in step (3), the drying conditions are vacuum drying at 100-200℃.

[0015] In summary, the present invention has the following beneficial effects: 1. In this invention, nylon resin primarily functions to reinforce the matrix, improve mechanical properties, and enhance interfacial bonding in the composite material. The dense structure and barrier effect of the filler effectively prevent the penetration of oxygen, water vapor, solvents, and other chemical substances, thereby improving the barrier properties of the composite material. Halogenated flame retardants absorb heat during combustion, lowering the material surface temperature and thus inhibiting the combustion reaction. Solubilizers have multiple functions in composite material preparation, including improving compatibility, increasing solubility, regulating processing properties, enhancing interfacial bonding, promoting reactions, regulating reaction rates, acting as plasticizers, and inducing filler dispersion. Plasticizers, by intercalating between polymer chains, weaken intermolecular forces, thereby increasing chain fluidity and making the material more easily deformable without breaking.

[0016] 2. In this invention, antioxidants and light stabilizers work synergistically to resist aging, forming a multi-layered protective system that significantly improves the UV resistance of the composite material. The synergistic toughening effect of nylon resin and fillers, and the synergistic effect of halogen-free flame retardants and nylon hydrogen bonds, achieve a balance between flame retardancy, anti-aging, and mechanical properties. Lubricants and solubilizers improve efficiency, and lightweight fillers reduce energy consumption. At the same time, it simplifies processing, reduces costs, and is environmentally friendly.

[0017] 3. The alkali lignin-based nitrogen-phosphorus flame retardant of this invention is modified by carboxymethylation. This process involves an etherification reaction under alkaline conditions, where the hydroxyl groups (-OH) in the lignin molecule combine with the carboxyl groups (-COOH) in sodium chloroacetate (ClCH2COONa) to form carboxymethyl groups (-CH2COO⁻). This increases the carboxyl content of the lignin, enhancing its hydrophilicity and dispersibility. The modification method is typically carried out under the catalysis of sodium hydroxide (NaOH). During the reaction, the chlorine atoms of sodium chloroacetate undergo a nucleophilic substitution reaction with the hydroxyl groups in the lignin molecule, generating carboxymethylated products and releasing hydrogen chloride.

[0018] 4. The synthesis mechanism of melamine-urea-formaldehyde resin in the alkali lignin-based nitrogen-phosphorus flame retardant of this invention is mainly based on the co-condensation reaction between melamine, urea, and glyoxal. Under alkaline conditions, glyoxal first undergoes a nucleophilic addition reaction with the amino group in urea to generate an intermediate containing a hydroxyl group, which then undergoes dehydration to form a carbon-nitrogen double bond structure. The amino group of melamine further reacts with this intermediate to form a stable conjugated structure, ultimately generating melamine-urea-glyoxal resin. The nitrogen compounds in diammonium hydrogen phosphate can react with phosphorus compounds to generate intermediates containing PN bonds. These intermediates act as more effective phosphorylation reagents, promoting the dehydration and carbonization of phosphorus, thereby enhancing the flame retardant effect. Carboxymethylation endows lignin with water solubility and metal chelating ability. Melamine-urea-glyoxal resin replaces the formaldehyde system, making it environmentally friendly and efficient, with a phosphorus-nitrogen-carbon ternary synergistic expansion flame retardant mechanism.

[0019] 5. The flame-retardant and anti-aging composite material obtained by this invention has high mechanical strength, a good balance between rigidity and toughness, and excellent high-temperature performance and chemical resistance. By adding fillers, halogen-free flame retardants, solubilizers, lubricants, antioxidants, light stabilizers, and plasticizers, the flame-retardant and anti-aging composite material lowers the surface temperature of the material, inhibits the generation of combustible gases, and simultaneously possesses high toughness, wear resistance, and self-lubricating properties.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the scope of protection of the present invention. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments can be obtained from commercially available sources.

[0022] Example Example 1 A flame-retardant and anti-aging composite material comprises the following components in parts by weight: 60 parts nylon resin, 15 parts filler, 5 parts halogen-free flame retardant, 3 parts solubilizer, 2.1 parts lubricant, 0.6 parts antioxidant, 0.5 parts light stabilizer and 1 part plasticizer. The halogen-free flame retardant is an alkali lignin-based nitrogen-phosphorus flame retardant. The alkali lignin-based nitrogen-phosphorus flame retardant is prepared by carboxylation modification of industrial alkali lignin with sodium chloroacetate to obtain water-soluble carboxymethyl alkali lignin. Melamine urea-formaldehyde resin is then synthesized using glyoxal, urea and melamine as raw materials. Subsequently, carboxymethyl alkali lignin, melamine urea-formaldehyde resin and diammonium hydrogen phosphate are compounded to obtain the final product.

[0023] The mass ratio of carboxymethyl alkali lignin, melamine urea-formaldehyde resin, and diammonium hydrogen phosphate is 1:2:1. The mass ratio of glyoxal, urea, and melamine in the melamine urea-formaldehyde resin is 1:2:1.

[0024] The filler is nano-titanium dioxide; the solubilizer is maleic anhydride-grafted polyolefin; the antioxidant is pentaerythritol tetra(3-lauryl thiopropionate); the light stabilizer is bis-2,2,6,6-tetramethylpiperidinol sebacate; and the plasticizer is di(2-ethylhexyl) phthalate.

[0025] A method for preparing a flame-retardant and anti-aging composite material includes the following steps: (1) Mix nylon resin, filler, halogen-free flame retardant, solubilizer, lubricant, antioxidant, light stabilizer and plasticizer to obtain a preliminary mixture; (2) The initial mixture is melted to obtain a molten mixture; (3) The molten mixture is dried under vacuum at 100°C to obtain a flame-retardant and anti-aging composite material.

[0026] Example 2 A flame-retardant and anti-aging composite material comprises the following components in parts by weight: 70 parts nylon resin, 20 parts filler, 12 parts halogen-free flame retardant, 5 parts solubilizer, 2.8 parts lubricant, 0.9 parts antioxidant, 1.8 parts light stabilizer and 2 parts plasticizer. The halogen-free flame retardant is an alkali lignin-based nitrogen-phosphorus flame retardant. The alkali lignin-based nitrogen-phosphorus flame retardant is prepared by carboxylation modification of industrial alkali lignin with sodium chloroacetate to obtain water-soluble carboxymethyl alkali lignin. Melamine urea-formaldehyde resin is then synthesized using glyoxal, urea and melamine as raw materials. Subsequently, carboxymethyl alkali lignin, melamine urea-formaldehyde resin and diammonium hydrogen phosphate are compounded to obtain the final product.

[0027] The mass ratio of carboxymethyl alkali lignin, melamine urea-formaldehyde resin, and diammonium hydrogen phosphate is 2:2:1. The mass ratio of glyoxal, urea, and melamine in the melamine urea-formaldehyde resin is 3:2:1.

[0028] The filler is nano-titanium dioxide; the solubilizer is maleic anhydride-grafted polyolefin; the antioxidant is pentaerythritol tetra(3-lauryl thiopropionate); the light stabilizer is bis-2,2,6,6-tetramethylpiperidinol sebacate; and the plasticizer is di(2-ethylhexyl) phthalate.

[0029] A method for preparing a flame-retardant and anti-aging composite material includes the following steps: (1) Mix nylon resin, filler, halogen-free flame retardant, solubilizer, lubricant, antioxidant, light stabilizer and plasticizer to obtain a preliminary mixture; (2) The initial mixture is melted to obtain a molten mixture; (3) The molten mixture is dried under vacuum at 150°C to obtain a flame-retardant and anti-aging composite material.

[0030] Example 3 A flame-retardant and anti-aging composite material comprises the following components in parts by weight: 80 parts nylon resin, 25 parts filler, 18 parts halogen-free flame retardant, 7 parts solubilizer, 3.5 parts lubricant, 1.2 parts antioxidant, 2.4 parts light stabilizer and 3 parts plasticizer. The halogen-free flame retardant is an alkali lignin-based nitrogen-phosphorus flame retardant. The alkali lignin-based nitrogen-phosphorus flame retardant is prepared by carboxylation modification of industrial alkali lignin with sodium chloroacetate to obtain water-soluble carboxymethyl alkali lignin. Melamine urea-formaldehyde resin is then synthesized using glyoxal, urea and melamine as raw materials. Subsequently, carboxymethyl alkali lignin, melamine urea-formaldehyde resin and diammonium hydrogen phosphate are compounded to obtain the final product.

[0031] The mass ratio of carboxymethyl alkali lignin, melamine urea-formaldehyde resin, and diammonium hydrogen phosphate is 2:3:1. The mass ratio of glyoxal, urea, and melamine in the melamine urea-formaldehyde resin is 4:3:2.

[0032] The filler is nano-titanium dioxide; the solubilizer is maleic anhydride-grafted polyolefin; the antioxidant is pentaerythritol tetra(3-lauryl thiopropionate); the light stabilizer is bis-2,2,6,6-tetramethylpiperidinol sebacate; and the plasticizer is di(2-ethylhexyl) phthalate.

[0033] A method for preparing a flame-retardant and anti-aging composite material includes the following steps: (1) Mix nylon resin, filler, halogen-free flame retardant, solubilizer, lubricant, antioxidant, light stabilizer and plasticizer to obtain a preliminary mixture; (2) The initial mixture is melted to obtain a molten mixture; (3) The molten mixture is dried under vacuum at 200°C to obtain a flame-retardant and anti-aging composite material.

[0034] Comparative Example 1 The flame-retardant and anti-aging composite material was prepared using the same method as in Example 1, except that no filler was added.

[0035] Comparative Example 2 The flame-retardant and anti-aging composite material was prepared using the same method as in Example 1, except that no halogen-free flame retardant was added.

[0036] Comparative Example 3 The flame-retardant and anti-aging composite material was prepared using the same method as in Example 1, except that the added alkali lignin-based nitrogen-phosphorus flame retardant was replaced with melamine polyphosphate.

[0037] Table 1 Performance Test Results As shown in Table 1, the flame-retardant and anti-aging composite material prepared in Example 1 has good flame retardancy and anti-aging properties, indicating that the prepared flame-retardant and anti-aging composite material has high mechanical strength, a good balance between rigidity and toughness, and excellent high-temperature performance and chemical resistance.

[0038] The above description is merely an exemplary embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A flame-retardant and anti-aging composite material, characterized in that, It includes the following components in parts by weight: 60-80 parts nylon resin, 15-25 parts filler, 5-18 parts halogen-free flame retardant, 3-7 parts solubilizer, 2.1-3.5 parts lubricant, 0.6-1.2 parts antioxidant, 0.5-2.4 parts light stabilizer and 1-3 parts plasticizer; The halogen-free flame retardant is an alkali lignin-based nitrogen-phosphorus flame retardant. The alkali lignin-based nitrogen-phosphorus flame retardant is prepared by carboxylation modification of industrial alkali lignin with sodium chloroacetate to obtain water-soluble carboxymethyl alkali lignin. Melamine urea-formaldehyde resin is then synthesized using glyoxal, urea, and melamine as raw materials. Subsequently, carboxymethyl alkali lignin, melamine urea-formaldehyde resin, and diammonium hydrogen phosphate are compounded to obtain the final product.

2. The flame-retardant and anti-aging composite material according to claim 1, characterized in that, The mass ratio of carboxymethyl alkali lignin, melamine urea-formaldehyde resin and diammonium hydrogen phosphate is 1-2:2-3:

1.

3. The flame-retardant and anti-aging composite material according to claim 1, characterized in that, The mass ratio of glyoxal, urea and melamine in the melamine-urea-formaldehyde resin is 1-4:2-3:1-2.

4. The flame-retardant and anti-aging composite material according to claim 1, characterized in that, The filler is one or more of nano-titanium dioxide, nano-zinc oxide, nano-montmorillonite, boron nitride, and nano-calcium titanate.

5. The flame-retardant and anti-aging composite material according to claim 1, characterized in that, The solubilizer is hexadecyltrimethylammonium bromide or maleic anhydride-grafted polyolefin.

6. The flame-retardant and anti-aging composite material according to claim 1, characterized in that, The antioxidant is one or more of bis(2,4-dicumylphenyl)pentaerythritol diphosphite, butylated hydroxytoluene, pentaerythritol tetra(3-lauryl thiopropionate), and sorbitol.

7. The flame-retardant and anti-aging composite material according to claim 1, characterized in that, The light stabilizer is one or more of bis-2,2,6,6-tetramethylpiperidine sebacate, polysuccinate, and bis(2,2,6,6-tetramethylpiperidine) sebacate.

8. The flame-retardant and anti-aging composite material according to claim 1, characterized in that, The plasticizer is one or more of di(2-ethylhexyl) phthalate, tris(1,3-dichloroisopropyl) phosphate, triisopropylphenyl phosphate, diphenylisodecyl phosphate, and methyl pentachlorostearate.

9. The method for preparing the flame-retardant and anti-aging composite material according to any one of claims 1-8, characterized in that, Includes the following steps: (1) Mix nylon resin, filler, halogen-free flame retardant, solubilizer, lubricant, antioxidant, light stabilizer and plasticizer to obtain a preliminary mixture; (2) The initial mixture is melted to obtain a molten mixture; (3) The molten mixture is dried to obtain a flame-retardant and anti-aging composite material.

10. The method for preparing the flame-retardant and anti-aging composite material according to claim 9, characterized in that, In step (3), the drying conditions are vacuum drying at 100-200℃.

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